EP-B-311 175 to Unilever discloses a liquid sanitising composition comprising at least 2% by weight of a caustic agent such as sodium hydroxide, from 0 to 1% of a surfactant, at least 3% by weight of an alkali metal hypochlorite and an alkali metal neutral silicate. The compositions disclosed in the EP-B-311 175 are used in industrial machines for bulk ware washing or fabrics washing to ensure an acceptable level of hygiene. The hypochlorite has a tendency to attack the dyes of a fabric and to reduce the integrity of the fabric per se.
Peroxygen bleaches are well known for their ability to remove stains from substrates. Generally, these systems need to be activated. One method of activation is to employ wash temperatures of 60° C. or higher. However, whilst these high temperatures provide a hygiene benefit they often lead to inefficient cleaning, and can also cause premature damage to the substrate.
A preferred approach to generating hydroperoxyl bleach radicals is the use of inorganic peroxides coupled with organic precursor compounds. These systems are employed for many commercial laundry powders. For example, various European systems are based on tetraacetyl ethylenediamine (TAED) as the organic precursor coupled with sodium perborate or sodium percarbonate, whereas in the United States laundry bleach products are typically based on sodium nonanoyloxybenzenesulphonate (SNOBS) as the organic precursor coupled with sodium perborate.
Precursor systems are generally effective but still exhibit several disadvantages. For example, organic precursors are moderately sophisticated molecules requiring multi-step manufacturing processes resulting in high capital costs. Also, precursor systems have large formulation space requirements so that a significant proportion of a laundry powder must be devoted to the bleach components, leaving less room for other active ingredients and complicating the development of concentrated powders. Moreover, precursor systems do not bleach very efficiently in countries where consumers have wash habits entailing low dosage, short wash times, cold temperatures and low wash liquor to substrate ratios.
UK patent 703,091 discloses a germicidal composition comprising a solution of iodine in a water soluble, nonionic surface-active agent having a polyglycol ether group.
UK patent 1,509,154 discloses an iodophore solution comprising a surfactant, which may be readily stirred and pumped with little tendency towards foaming.